| persistence and expression of cotesia congregata polydnavirus in host larvae of the tobacco hornworm, manduca sexta. | the gregarious braconid wasp cotesia congregata parasitizes host larvae of manduca sexta, and several other sphingid species. parasitism induces host immunosuppression due to the disruptive action of the wasp's polydnavirus (pdv) on host blood cells. during the initial stages of parasitism, these cells undergo apoptosis followed by cell clumping, which clears the hemolymph of a large number of cells. in this study, the persistence and expression of cotesia congregata pdv (ccpdv) were examined us ... | 2003 | 12770632 |
| point mutagenesis reveals that a coiled-coil motif of crv1 is required for entry to hemocytes to suppress cellular immune responses. | various immunosuppressive factors are derived from polydnaviruses (pdvs) mutually symbiotic to some ichneumonid and braconid wasps. crv1 was originally identified from a pdv called cotesia rubecula bracovirus. crv1 orthologs are reported in other cotesia-associated pdvs, but not clearly understood in their physiological functions. this study determined a function of crv1 encoded in cotesia plutellae bracovirus (cpbv). cpbv-crv1 is the largest molecule among the known crv1s and is predicted to po ... | 2014 | 25072922 |
| identification of an in vitro interaction between an insect immune suppressor protein (crv2) and g alpha proteins. | the protein crv2 is encoded by a polydnavirus integrated into the genome of the endoparasitoid cotesia rubecula (hymenoptera:braconidae:microgastrinae) and is expressed in host larvae with other gene products of the polydnavirus to allow successful development of the parasitoid. crv2 expression has previously been associated with immune suppression, although the molecular basis for this was not known. here, we have used time-resolved förster resonance energy transfer (tr-fret) to demonstrate hig ... | 2011 | 21233205 |
| ectopic expression of an endoparasitic wasp venom protein in drosophila melanogaster affects immune function, larval development and oviposition. | endoparasitic hymenoptera inject maternal factors into the host, along with their eggs, to subvert the host immune system. the venom protein, vn50, previously characterized from the wasp cotesia rubecula inhibits prophenoloxidase activation in its host pieris rapae and in another lepidopteran, manduca sexta. we generated a stable line in the model insect, drosophila melanogaster, which ectopically expresses vn50. results indicated that vn50 expression accelerates larval development, increases ov ... | 2010 | 20408903 |
| isoprene interferes with the attraction of bodyguards by herbaceous plants. | isoprene is the most abundant volatile compound emitted by vegetation. it influences air chemistry and is part of plant defense against abiotic stresses. however, whether isoprene influences biotic interactions between plants and other organisms has not been investigated to date. here we show a new effect of isoprene, namely its influence on interactions between plants and insects. herbivory induces the release of plant volatiles that attract the herbivore's enemies, such as parasitic wasps, as ... | 2008 | 18987312 |
| the effect of resource aggregation at different scales: optimal foraging behavior of cotesia rubecula. | resources can be aggregated both within and between patches. in this article, we examine how aggregation at these different scales influences the behavior and performance of foragers. we developed an optimal foraging model of the foraging behavior of the parasitoid wasp cotesia rubecula parasitizing the larvae of the cabbage butterfly pieris rapae. the optimal behavior was found using stochastic dynamic programming. the most interesting and novel result is that the effect of resource aggregation ... | 2001 | 18707305 |
| differential effectiveness of microbially induced resistance against herbivorous insects in arabidopsis. | rhizobacteria-induced systemic resistance (isr) and pathogen-induced systemic acquired resistance (sar) have a broad, yet partly distinct, range of effectiveness against pathogenic microorganisms. here, we investigated the effectiveness of isr and sar in arabidopsis against the tissue-chewing insects pieris rapae and spodoptera exigua. resistance against insects consists of direct defense, such as the production of toxins and feeding deterrents and indirect defense such as the production of plan ... | 2008 | 18533832 |
| differential expression of the crv1 haemocyte inactivation-associated polydnavirus gene in the african maize stem borer busseola fusca (fuller) parasitized by two biotypes of the endoparasitoid cotesia sesamiae (cameron). | polydnaviruses are rarely studied for their natural variation in immune suppressive abilities. the polydnavirus harboring braconid cotesia sesamiae, a widespread endoparasitoid of busseola fusca and sesamia calamistis in sub-saharan africa exists as two biotypes. in kenya, the western biotype completes development in b. fusca larvae. however, eggs of the coastal c. sesamiae are encapsulated in this host and ultimately, no parasitoids emerge from parasitized b. fusca larvae. both biotypes develop ... | 2007 | 17570392 |
| are insect immune suppressors driving cellular uptake reactions? | many insect parasitoids that deposit their eggs inside immature stages of other insect species inactivate the cellular host defence to protect the growing embryo from encapsulation. suppression of encapsulation by polydnavirus-encoded immune-suppressors correlates with specific alterations in hemocytes, mainly cytoskeletal rearrangements and actin-cytoskeleton breakdown. we have previously shown that the cotesia rubecula polydnavirus gene product crv1 causes immune suppression when injected into ... | 2005 | 16304617 |
| parasitization of manduca sexta larvae by the parasitoid wasp cotesia congregata induces an impaired host immune response. | during oviposition, the parasitoid wasp cotesia congregata injects polydnavirus, venom, and parasitoid eggs into larvae of its lepidopteran host, the tobacco hornworm, manduca sexta. polydnaviruses (pdvs) suppress the immune system of the host and allow the juvenile parasitoids to develop without being encapsulated by host hemocytes mobilized by the immune system. previous work identified a gene in the cotesia rubecula pdv (crv1) that is responsible for depolymerization of actin in hemocytes of ... | 2005 | 15893997 |
| a serine proteinase homolog venom protein from an endoparasitoid wasp inhibits melanization of the host hemolymph. | activation of prophenoloxidase (propo) in insects is a defense mechanism against intruding microorganisms and parasites. pattern recognition molecules induce activation of an enzymatic cascade involving serine proteinases, which leads to the conversion of propo to active phenoloxidase (po). phenolic compounds produced by ppo-activation are toxic to invaders. here, we describe the isolation of a venom protein from the parasitoid, cotesia rubecula, injected into the host, pieris rapae, which is ho ... | 2003 | 14505695 |
| isolation and characterization of a cotesia rubecula bracovirus gene expressed in the lepidopteran pieris rapae. | polydnaviruses are endogenous particles that are crucial for the survival of endoparasitoid wasps, providing active suppression of the immune function of the lepidopteran host in which wasp larvae develop. the cotesia rubecula bracovirus (crbv) is unique in that only four gene products are detected in larval host (pieris rapae) tissues and expression of crbv genes is transient, occurring between 4 and 12 h post-parasitization. two of the four genes, crv1 and crv3, have been characterized. crv1 i ... | 2004 | 15448349 |
| negative regulation of prophenoloxidase (propo) activation by a clip-domain serine proteinase homolog (sph) from endoparasitoid venom. | most parasitic wasps inject maternal factors into the host hemocoel to suppress the host immune system and ensure successful development of their progeny. melanization is one of the insect defence mechanisms against intruding pathogens or parasites. we previously isolated from the venom of cotesia rubecula a 50 kda protein that blocked melanization in the hemolymph of its host, pieris rapae [insect biochem. mol. biol. 33 (2003) 1017]. this protein, designated vn50, is a serine proteinase homolog ... | 2004 | 15110869 |
| characterization of a novel protein with homology to c-type lectins expressed by the cotesia rubecula bracovirus in larvae of the lepidopteran host, pieris rapae. | polydnaviruses are essential for the survival of many ichneumonoid endoparasitoids, providing active immune suppression of the host in which parasitoid larvae develop. the cotesia rubecula bracovirus is unique among polydnaviruses in that only four major genes are detected in parasitized host (pieris rapae) tissues, and gene expression is transient. here we describe a novel c. rubecula bracovirus gene (crv3) encoding a lectin monomer composed of 159 amino acids, which has conserved residues cons ... | 2003 | 12644452 |
| a coiled-coil region of an insect immune suppressor protein is involved in binding and uptake by hemocytes. | polydnaviruses are associated with certain parasitoid wasps and are introduced into the body cavity of the host caterpillar during oviposition. some of the viral genes are expressed in host tissues and corresponding proteins are secreted into the hemocoel causing suppression of the host immune system. the cotesia rubecula polydnavirus gene product, crv1, effectively inactivates hemocytes by mediating cytoskeleton breakdown. a precondition for the crv1 function is the incorporation of the extrace ... | 2002 | 11891126 |
| promoter studies of a polydnavirus gene from cotesia rubecula (hym: braconidae). | the cotesia rubecula polydnavirus gene, crv1, is expressed in a highly transient fashion. within four hours after egg deposition and virus infection, tissues of the host caterpillar, pieris rapae, express high levels of the transcript. twelve hours after infection no transcripts are visible. we have previously shown that the crv1 secreted protein is mainly produced in host haemocytes. in haemocytes, immune functions such as phagocytosis and cell spreading are abolished by destabilization of the ... | 2001 | 11722018 |
| plant-natural enemy association in the tritrophic system,cotesia rubecula-pieris rapae-brassiceae (cruciferae): i. sources of infochemicals. | the role of airborne infochemicals in host selection by the parasitoidcotesia rubecula (marshal) (hymenoptera: braconidae) was examined in a wind tunnel. to elucidate the role of volatile chemicals in attractingc. rubecula to cabbage infested by the host [pieris rapae l. (lepidoptera: pieridae)], the potential sources of volatiles related top. rapae infestation on cabbage were tested individually. the responses of females to nonhost plant species, bean and geranium, as well as to frass of a nonh ... | 1994 | 24242665 |
| smelling the wood from the trees: non-linear parasitoid responses to volatile attractants produced by wild and cultivated cabbage. | despite a large number of studies on herbivore-induced plant volatiles (hipvs), little is known about which specific compounds are used by natural enemies to locate prey- or host- infested plants. in addition, the role of hipvs in attracting natural enemies has been restricted largely to agricultural systems. differences in volatile blends emitted by cultivars and plants that originate from wild populations may be attributed to potentially contrasting selection regimes: natural selection among t ... | 2011 | 21748300 |
| sex determination meltdown upon biological control introduction of the parasitoid cotesia rubecula? | natural enemies may go through genetic bottlenecks during the process of biological control introductions. such bottlenecks are expected to be particularly detrimental in parasitoid hymenoptera that exhibit complementary sex determination (csd). csd is associated with a severe form of inbreeding depression because homozygosity at one or multiple sex loci leads to the production of diploid males that are typically unviable or sterile. we observed that diploid males occur at a relatively high rate ... | 2012 | 22949920 |
| balancing selection maintains sex determining alleles in multiple-locus complementary sex determination. | hymenopteran species in which sex is determined through a haplo-diploid mechanism known as complementary sex determination (csd) are vulnerable to a unique form of inbreeding depression. diploids heterozygous at one or more csd loci develop into females but diploids homozygous at all loci develop into diploid males, which are generally sterile or inviable. species with multiple polymorphic csd loci (ml-csd) may have lower rates of diploid male production than species with a single csd locus (sl- ... | 2017 | 28225571 |
| antennal sensilla of two parasitoid wasps: a comparative scanning electron microscopy study. | two closely related parasitoid wasp species, cotesia glomerata (l.) and cotesia rubecula (marshall) (hymenoptera:braconidae), are different in their associative learning of plant odors. to provide a solid basis for our research on the mechanisms that underlie this difference, we described the morphology of the antennal sensilla of these two species using scanning electron microscopy complemented with transmission electron microscopy. female and male antennae of both species have the same six typ ... | 2004 | 15170756 |
| herbivore-induced plant volatiles mediate in-flight host discrimination by parasitoids. | herbivore feeding induces plants to emit volatiles that are detectable and reliable cues for foraging parasitoids, which allows them to perform oriented host searching. we investigated whether these plant volatiles play a role in avoiding parasitoid competition by discriminating parasitized from unparasitized hosts in flight. in a wind tunnel set-up, we used mechanically damaged plants treated with regurgitant containing elicitors to simulate and standardize herbivore feeding. the solitary paras ... | 2005 | 16132211 |
| species-specific acquisition and consolidation of long-term memory in parasitic wasps. | long-term memory (ltm) formation usually requires repeated, spaced learning events and is achieved by the synthesis of specific proteins. other memory forms require a single learning experience and are independent of protein synthesis. we investigated in two closely related parasitic wasp species, cotesia glomerata and cotesia rubecula, whether natural differences in foraging behaviour are correlated with differences in ltm acquisition and formation. these parasitic wasp species lay their eggs i ... | 2007 | 17439855 |
| creb expression in the brains of two closely related parasitic wasp species that differ in long-term memory formation. | the camp/pka signalling pathway and transcription factor camp response element-binding protein (creb) play key roles in long-term memory (ltm) formation. we used two closely related parasitic wasp species, cotesia glomerata and cotesia rubecula, which were previously shown to be different in ltm formation, and sequenced at least nine different creb transcripts in both wasp species. the splicing patterns, functional domains and amino acid sequences were similar to those found in the creb genes of ... | 2010 | 20236366 |
| differentially expressed genes linked to natural variation in long-term memory formation in cotesia parasitic wasps. | even though learning and memory are universal traits in the animal kingdom, closely related species reveal substantial variation in learning rate and memory dynamics. to determine the genetic background of this natural variation, we studied two congeneric parasitic wasp species, cotesia glomerata and c. rubecula, which lay their eggs in caterpillars of the large and small cabbage white butterfly. a successful egg laying event serves as an unconditioned stimulus (us) in a classical conditioning p ... | 2015 | 26557061 |
| impact of herbivore-induced plant volatiles on parasitoid foraging success: a spatial simulation of the cotesia rubecula, pieris rapae, and brassica oleracea system. | many parasitoids are known to use herbivore-induced plant volatiles as cues to locate hosts. however, data are lacking on how much of an advantage a parasitoid can gain from following these plant cues and which factors can limit the value of these cues to the parasitoid. in this study, we simulate the cotesia rubecula-pieris rapae-brassica oleracea system, and ask how many more hosts can a parasitoid attack in a single day of foraging by following plant signals versus randomly foraging. we vary ... | 2008 | 18438615 |
| genetic variation in defense chemistry in wild cabbages affects herbivores and their endoparasitoids. | populations of wild brassica oleracea l. grow naturally along the atlantic coastlines of the united kingdom and france. over a very small spatial scale (i.e., <15 km) these populations differ in the expression of the defensive compounds, glucosinolates (gs). thus far, very few studies have examined interactions between genetically distinct populations of a wild plant species and associated consumers in a multitrophic framework. here, we compared the development of a specialist (pieris rapae) and ... | 2008 | 18589526 |
| herbivore-induced volatile production by arabidopsis thaliana leads to attraction of the parasitoid cotesia rubecula: chemical, behavioral, and gene-expression analysis. | many plant species defend themselves against herbivorous insects indirectly by producing volatiles in response to herbivory. these volatiles attract carnivorous enemies of the herbivores. research on the model plant arabidopsis thaliana (l.) heynh. has contributed considerably to the unraveling of signal transduction pathways involved in direct plant defense mechanisms against pathogens. here, we demonstrate that arabidopsis is also a good candidate for studying signal transduction pathways invo ... | 2001 | 11710601 |
| induced parasitoid attraction by arabidopsis thaliana: involvement of the octadecanoid and the salicylic acid pathway. | plants can use indirect defence mechanisms to protect themselves against herbivorous insects. an example of such an indirect defence mechanism is the emission of volatiles by plants induced by herbivore feeding. these volatiles can attract the natural enemies of these herbivores, for example, parasitoid wasps. here, it is shown that the octadecanoid and the salicylic acid pathways are involved in the induced attraction of the parasitoid wasp cotesia rubecula by arabidopsis thaliana infested with ... | 2002 | 12147729 |
| formation of simple nitriles upon glucosinolate hydrolysis affects direct and indirect defense against the specialist herbivore, pieris rapae. | the glucosinolate-myrosinase system, found in plants of the order brassicales, has long been considered an effective defense system against herbivores. the defensive potential of glucosinolates is mainly due to the products formed after myrosinase-catalyzed hydrolysis upon tissue damage. the most prominent hydrolysis products, the isothiocyanates, are toxic to a wide range of organisms, including herbivorous lepidopterans. in contrast, little is known about the biological activities of alternati ... | 2008 | 18787901 |
| inhibition of melanization by a parasitoid serine protease homolog venom protein requires both the clip and the non-catalytic protease-like domains. | endoparasitoid wasps inject a variety of components into their host hemocoel at oviposition to facilitate successful development of their progeny. among these are venom proteins which have been shown to play crucial roles in host regulation. a serine protease homolog (sph)-like venom protein from cotesia rubecula was previously shown to inhibit melanization in the host hemolymph by blocking activation of prophenoloxidase to phenoloxidase, a key enzyme in melanin formation. similar to other sphs, ... | 2011 | 26467830 |
| proteomic analysis of the venom from the endoparasitoid wasp pteromalus puparum (hymenoptera: pteromalidae). | parasitoid venom is a complex mixture of active substances with diversified biological functions. because of its range of activities, venom is an important resource with respect to potential application in agriculture and medicine. only a limited number of peptides, proteins, and enzymes have been identified and characterized from parasitoid venom. here we describe a proteomic analysis of the venom from the endoparasitoid wasp pteromalus puparum (hymenoptera: pteromalidae). venom resolved by two ... | 2010 | 20648599 |
| endoparasitoid wasp bracovirus-mediated inhibition of hemolin function and lepidopteran host immunosuppression. | successful embryonic development of parasitoid wasps in lepidopteran hosts is achieved through co-injection of polydna viruses whose gene products are thought to target the immune responses of the host. one gene product of the endosymbiont bracovirus of the parasitic wasp cotesia rubecula, crv1, has been reported to inhibit the immune responses of its endoparasitized lepidopteran host through interference with the haematocyte cytoskeletal structure. here we establish that ccv1, the cotesia congr ... | 2008 | 18627380 |
| a calreticulin-like protein from endoparasitoid venom fluid is involved in host hemocyte inactivation. | during oviposition, most endoparasitoid wasps inject maternal factors into their hosts to interfere with host immune reactions and ensure successful development of their progeny. since encapsulation is a major cellular defensive response of insects against intruding parasites, parasitoids have developed numerous mechanisms to suppress the host encapsulation capability by interfering with every step in the process, including recognition, adherence and spreading. in previous studies, components of ... | 2006 | 16364437 |
| a novel venom peptide from an endoparasitoid wasp is required for expression of polydnavirus genes in host hemocytes. | maternal factors introduced into host insects by endoparasitoid wasps are usually essential for successful parasitism. this includes polydnaviruses (pdvs) that are produced in the reproductive organ of female hymenopteran endoparasitoids and are injected, together with venom proteins, into the host hemocoel at oviposition. inside the host, pdvs enter various tissue cells and hemocytes where viral genes are expressed, leading to developmental and physiological alterations in the host, including t ... | 2004 | 15292189 |
| isolation of an imaginal disc growth factor homologue from pieris rapae and its expression following parasitization by cotesia rubecula. | endoparasitoid insects introduce maternal factors into the body of their host at oviposition to suppress cellular defences for the protection of the developing parasitoid. we have shown that transient expression of polydnavirus genes from a hymenopteran parasitoid cotesia rubecula (crpdv) is responsible for the inactivation of hemocytes from the lepidopteran host pieris rapae. since the observed downregulation of crpdv genes in infected host tissues is not due to cis-regulatory elements at the c ... | 2004 | 15288202 |
| development of the parasitoid, cotesia rubecula (hymenoptera: braconidae) in pieris rapae and pieris brassicae (lepidoptera: pieridae): evidence for host regulation. | several recent models examining the developmental strategies of parasitoids attacking hosts which continue feeding and growing after parasitism (=koinobiont parasitoids) assume that host quality is a non-linear function of host size at oviposition. we tested this assumption by comparing the growth and development of males of the solitary koinobiont endoparasitoid, cotesia rubecula, in first (l1) to third (l3) larval instars of its preferred host, pieris rapae and in a less preferred host, pieris ... | 1999 | 12770386 |
| isolation and characterization of a novel venom protein from an endoparasitoid, cotesia rubecula (hym: braconidae). | insects are important vectors of diseases with remarkable immune defense capabilities. hymenopteran endoparasitoids are adapted to overcome the host defense system and, therefore, are useful sources of immune-suppressing proteins. not much is known about venom proteins in endoparasitoids, especially those that have a functional relationship with polydnaviruses (pdvs). here, we describe the isolation and characterization of a small venom protein (vn4.6) from an endoparasitoid, cotesia rubecula, w ... | 2003 | 12761876 |
| polydnavirus particle proteins with similarities to molecular chaperones, heat-shock protein 70 and calreticulin. | multipartite nucleic acid-containing virus-like particles, known as polydnaviruses, are special structures produced by female parasitoid wasps to deliver wasp components into the body of their host at oviposition. the particles confer protection for the developing parasitoid by passive and active means. although several genes expressed from the circular dna of these particles have been identified from various host-parasitoid systems, there is not much known about the structural proteins of these ... | 2003 | 12692281 |
| host haemocyte inactivation by an insect parasitoid: transient expression of a polydnavirus gene. | polydnaviruses produced by the hymenopteran endoparasitoid cotesia rubecula are deposited together with the egg into the lepidopteran host pieris rapae and are apparently involved in the suppression of the host's defence system. around 6 h post-parasitization host haemocytes change their surface properties, actin cytoskeleton structure and adhesion properties. here we show that a single polydnavirus gene is expressed inside the caterpillar haemocytes in a transient fashion between 4 to 8 h post- ... | 1996 | 8887503 |
| plant-natural enemy association in tritrophic system,cotesia rubecula-pieris rapae-brassicaceae (cruciferae). iii: collection and identification of plant and frass volatiles. | to elucidate the identity of the volatile compounds that could be involved in the searching behavior of the parasitoidcotesia rubecula marshall (hymenoptera: braconidae), the volatiles released by cabbage and frass of lepidoptera feeding on cabbage were collected and analyzed using a gas chromatograph-mass spectrometer. the volatiles emitted by intact cabbage were α-pinene, β-pinene, myrcene, 1,8-cineole,n-hexyl acetate,cis-3-hexen-1-yl acetate, and dimethyl trisulfide. mechanical damage on an i ... | 1994 | 24242722 |